Improvement in chucks



'UNITED STATES PATENT OFFICE.

LEANDER PARMELEE, OF NEW HAVEN, CONN EOTIOUT, ASSIGNOR TO HIMSELF AND MERRITT HINE, OF SAME PLAGE.

|MPRovi-:MENT IN cHucKs.

Specification forming part of Letters Patent No. 144,128, dated October 28, 1873; application filed October 1, 1873.

To all whom t may concern:

Be it known that I, LEANDEE PAEMELEE, of New Haven, in the county of New Haven and State of Connecticut, have invented a new Improvement in Drill-Chucks 5 and I do hereby declare the following, when taken in connection with the accompanying drawings and the letters of reference marked thereon, to be a full,

clear, and exact description of the same, andQ which said drawings constitute part of this specification, and represent, in

ligure l, a side view and in Fig. 2, a longitudinal central section, showing one jaw.

This invention relates to an improvement in the chuck invented by me, and for which an application for patent was filed May 2S, 1873, and allowed September 17 187 3 5 the object being to allow the free action of the jaws to be self-adjusting upon the drill-chuck, and yet to insure their like relative position to the axis of the chuck, and the invention consists in the arrangement of a plate or disk in the rear of the jaws, with a spring-pressure behind it to bear against the rear end of the jaws, so that the turning of one jaw to an angle will depress the disk, and allow the other jaws to assume the same angle.

A is the head of the chuck, attached to, or made a pa-rt of, a threaded spindle, B, which extends back and is fitted to the mandrel of the lathe. In this head A are arranged two or more levers, O, (preferably three.) These levers are pivoted in the head, as at a. Upon to be moved longitudinally by means of the thread on the spindle B. The other extreme of the levers rests upon this conical surface, so that, by forcing the sleeve toward the head, the ends of the levers will be raised, and the jaws depressed, and vice versa. Beneath the levers, forward of the pivot, a suitable spring', f, is arranged, the tendency of which is to force open the jaws when the sleeve E is withdrawn. In order that the jaws shall always be in the same position to eachother, I arrange between the jaws and the head a disk, F, with a shank, G, running back into the head, so as to firmly support the disk, and prevent any other than a longitudinal movement. disk, and preferably so as to bear against the shank, I arrange a spring, N, the tendency of which is to bear the disk F hard again st the rear end of the jaws, so that the rear end of the jaws will, when free, lie ilat against the disk, but, ifa tapering tool or article be placed between the j aws so that when the jaws are forced thereon it will turn them out of line, the plate will be depressed to the saine extent in the rear of all the jaws, and thus insure the equal inelination of the said jaws.

This disk is applicable to other constructions haxng loose jaws.

I claim as my invention- The head A, having two 0r more levers, O O, arranged therein, provided with a spindle, B, and conical sleeve E, and the jaws pivoted upon the forward end of the lever, combined with the disk F in the rear of the said jaws,

and a spring-pressure thereon, substantially as herein set forth.

LEANDER PARMELEE. Witnesses A. J TrBErTs, J. E. SHUMWAY.

In the rear of this Y 

